This invention relates generally to heat pumps using solid adsorbent beds and more particularly to such heat pumps in which the refrigerant for the heat pump loop also serves both to heat and cool the beds.
Heat driven solid adsorbent bed heat pumps have been available for many years. Heretofore, however, the beds were heated with one medium while another medium served as the refrigerant. Such heat driven heat pump systems required some sort of heat exchanger in each of the adsorbent beds to isolate the heating medium from the refrigerant. Examples of these prior art systems are set forth in the following patents:
______________________________________ U.S. Pat. No. Issue Date Inventor ______________________________________ 1,833,901 12/1/31 Hull 2,024,083 12/1935 Young 2,131,119 9/27/38 Root, et al. 3,007,543 11/07/61 J.L. Maher 3,828,566 8/13/74 Wetzel 4,183,227 1/15/80 Bouvin, et al. 4,548,046 10/22/85 Brandon, et al. 4,610,148 9/9/86 Shelton 4,694,659 9/22/87 Shelton 4,709,558 12/01/87 Matsushita, et al. 4,881,376 11/21/89 Yonezawa, et al. 4,944,159 07/31/90 Crozat 4,976,117 12/11/90 Crozat, et al. 5,005,371 04/09/91 Yonezawa, et al. 5,046,319 9/10/1991 Jones ______________________________________
The presence of the heat exchanger to maintain the refrigerant separate from the heat exchange fluid significantly reduces the heat transfer rate from the heat exchange fluid to the sorbent. Furthermore, the mass of the heat exchanger itself significantly reduces the heat transfer from the heat exchange fluid to the sorbent since the mass of the heat exchanger must be thermally cycled along with the sorbent material. Both of these factors have a detrimental effect on the performance of the solid adsorbent bed heat pump.